/* handy hash variants */

#include "nyara.h"
#include <ruby/st.h>
#include "inc/str_intern.h"

VALUE nyara_param_hash_class;
VALUE nyara_header_hash_class;
VALUE nyara_config_hash_class;

// stolen from hash.c
int nyara_rb_hash_has_key(VALUE hash, VALUE key) {
  if (!RHASH(hash)->ntbl)
    return 0;
  if (st_lookup(RHASH(hash)->ntbl, key, 0))
    return 1;
  return 0;
}

// NOTE no need to add lots of methods like HashWithIndifferentAccess
//      just return simple hash like rack

static VALUE param_hash_aref(VALUE self, VALUE key) {
  if (TYPE(key) == T_SYMBOL) {
    key = rb_sym_to_s(key);
  }
  return rb_hash_aref(self, key);
}

static VALUE param_hash_key_p(VALUE self, VALUE key) {
  if (TYPE(key) == T_SYMBOL) {
    key = rb_sym_to_s(key);
  }
  return nyara_rb_hash_has_key(self, key) ? Qtrue : Qfalse;
}

static VALUE param_hash_aset(VALUE self, VALUE key, VALUE value) {
  if (TYPE(key) == T_SYMBOL) {
    key = rb_sym_to_s(key);
  }
  return rb_hash_aset(self, key, value);
}

void nyara_headerlize(VALUE str) {
  char* s = (char*)RSTRING_PTR(str);
  long len = RSTRING_LEN(str);
  int border = 1;
  for (long i = 0; i < len; i++) {
    if (s[i] == '-') {
      border = 1;
      continue;
    }
    if (border) {
      // note this is most reliable way,
      // with <ctype.h> we have to deal with locale...
      if (s[i] >= 'a' && s[i] <= 'z') {
        s[i] = 'A' + (s[i] - 'a');
      }
      border = 0;
    } else {
      if (s[i] >= 'A' && s[i] <= 'Z') {
        s[i] = 'a' + (s[i] - 'A');
      }
    }
  }
}

static VALUE header_hash_tidy_key(VALUE key) {
  if (TYPE(key) == T_SYMBOL) {
    key = rb_sym_to_s(key);
  } else {
    Check_Type(key, T_STRING);
    key = rb_enc_str_new(RSTRING_PTR(key), RSTRING_LEN(key), u8_encoding);
  }
  nyara_headerlize(key);
  return key;
}

static VALUE header_hash_aref(VALUE self, VALUE key) {
  return rb_hash_aref(self, header_hash_tidy_key(key));
}

static VALUE header_hash_key_p(VALUE self, VALUE key) {
  return nyara_rb_hash_has_key(self, header_hash_tidy_key(key)) ? Qtrue : Qfalse;
}

static ID id_to_s;
static VALUE header_hash_aset(VALUE self, VALUE key, VALUE value) {
  key = header_hash_tidy_key(key);
  if (TYPE(value) != T_STRING) {
    value = rb_funcall(value, id_to_s, 0);
  }

  return rb_hash_aset(self, key, value);
}

static int header_hash_merge_func(VALUE k, VALUE v, VALUE self_st) {
  st_table* t = (st_table*)self_st;
  if (!st_is_member(t, k)) {
    st_insert(t, (st_data_t)k, (st_data_t)v);
  }
  return ST_CONTINUE;
}

static VALUE header_hash_reverse_merge_bang(VALUE self, VALUE other) {
  if (!rb_obj_is_kind_of(other, nyara_header_hash_class)) {
    rb_raise(rb_eArgError, "need a Nyara::HeaderHash");
  }
  st_table* t = rb_hash_tbl(self);
  rb_hash_foreach(other, header_hash_merge_func, (VALUE)t);
  return self;
}

static int header_hash_serialize_func(VALUE k, VALUE v, VALUE arr) {
  long vlen = RSTRING_LEN(v);
  // deleted field
  if (vlen == 0) {
    return ST_CONTINUE;
  }

  long klen = RSTRING_LEN(k);
  long capa = klen + vlen + 4;
  volatile VALUE s = rb_str_buf_new(capa);
  sprintf(RSTRING_PTR(s), "%.*s: %.*s\r\n", (int)klen, RSTRING_PTR(k), (int)vlen, RSTRING_PTR(v));
  STR_SET_LEN(s, capa);
  rb_enc_associate(s, u8_encoding);
  rb_ary_push(arr, s);
  return ST_CONTINUE;
}

static VALUE header_hash_serialize(VALUE self) {
# ifdef HAVE_RB_ARY_NEW_CAPA
  long size = (!RHASH(self)->ntbl ? RHASH(self)->ntbl->num_entries : 0);
  volatile VALUE arr = rb_ary_new_capa(size);
# else
  volatile VALUE arr = rb_ary_new();
# endif
  rb_hash_foreach(self, header_hash_serialize_func, arr);
  return arr;
}

void Init_hashes(VALUE nyara) {
  id_to_s = rb_intern("to_s");

  nyara_param_hash_class = rb_define_class_under(nyara, "ParamHash", rb_cHash);
  nyara_header_hash_class = rb_define_class_under(nyara, "HeaderHash", nyara_param_hash_class);
  nyara_config_hash_class = rb_define_class_under(nyara, "ConfigHash", nyara_param_hash_class);

  rb_define_method(nyara_param_hash_class, "[]", param_hash_aref, 1);
  rb_define_method(nyara_param_hash_class, "key?", param_hash_key_p, 1);
  rb_define_method(nyara_param_hash_class, "[]=", param_hash_aset, 2);

  rb_define_method(nyara_header_hash_class, "[]", header_hash_aref, 1);
  rb_define_method(nyara_header_hash_class, "key?", header_hash_key_p, 1);
  rb_define_method(nyara_header_hash_class, "[]=", header_hash_aset, 2);
  rb_define_method(nyara_header_hash_class, "reverse_merge!", header_hash_reverse_merge_bang, 1);
  rb_define_method(nyara_header_hash_class, "serialize", header_hash_serialize, 0);

  // for internal use
  rb_define_method(nyara_header_hash_class, "_aset", rb_hash_aset, 2);
  rb_define_method(nyara_header_hash_class, "_aref", rb_hash_aref, 1);
}